In February 1915, a small committee in Alexandria approved a plan of Zeev Jabotinsky and Joseph Trumpeldor to form a military unit from Russian Jewish émigrés from Palestine that would participate in the British effort to "liberate" Palestine from the Ottoman Empire.[1] The British commander General Maxwell met a delegation, led by Jabotinsky, on 15 March. The General said he was unable, under the Army Act, to enlist foreign nationals as fighting troops, but that he could form them into a volunteer transport Mule Corps.[1][2] Jabotinsky rejected the idea and left for Europe to seek other support for a Jewish unit, but Trumpeldor accepted it and began recruiting volunteers from among the Jews in Egypt who had been deported there by the Ottomans in the previous year.[1] The British Army formed 650 of them into the Zion Mule Corps, of which 562 served in the Gallipoli Campaign.[1]

The need on the Gallipoli peninsula for means to carry water to the troops was considered so urgent that in mid-April, a request was forwarded to Egypt for the Zion Mule Corps to be sent immediately, regardless of its lack of equipment.[3] Its Commanding Officer was Lieutenant-ColonelJohn Henry Patterson, DSO, an Irish Protestant, and Captain Trumpeldor was Second-in-command. The Zion Mule Corps landed at Cape Helles from 27–28 April, four weeks after being raised, having been stranded at Mudros when its ship ran aground. The corps was embarked in the same ship as the Indian 9th Mule Corps bound for Gaba Tepe and so a detour to Helles was ordered. The Zion Mule Corps was disembarked under artillery fire from the Asiatic shore, with help of volunteers from the 9th Mule Corps and began carrying supplies forward immediately.[4]

A Distinguished Conduct Medal was awarded to Private M. Groushkowsky, who, near Krithia on 5 May, prevented his mules from stampeding under heavy bombardment and despite being wounded in both arms, delivered the ammunition.[5] Trumpeldor was shot through the shoulder but refused to leave the battlefield.[6] Patterson later wrote: "Many of the Zionists whom I thought somewhat lacking in courage showed themselves fearless to a degree when under heavy fire, while Captain Trumpeldor actually revelled in it, and the hotter it became the more he liked it ..."

The men returned to Alexandria on 10 January 1916. The Zion Mule Corps were disbanded on 26 May 1916. The Commonwealth War Graves Commission lists 13 members of the Zion Mule Corps as fatalities.[7]

Between the dissolution of the Zion Mule Corps and the formation of the Jewish Legion, Jabotinsky and Trumpeldor and 120 Zion Mule Corps veterans served together in 16 Platoon of the 20th Battalion, London Regiment.

Finally, in August 1917, the formation of a Jewish battalion was officially announced. The unit was designated as the 38th Battalion of the Royal Fusiliers and included British volunteers, as well as members of the former Zion Mule Corps and a large number of Russian Jews. In April 1918, it was joined by the 39th Battalion, raised at Fort Edward, Nova Scotia, which was made up almost entirely of Jews who were resident in the United States and Canada.[8]

Thousands of Palestinian Jews also applied to join the Legion and in 1918, more than 1,000 were enlisted. Ninety-two Ottoman Jews who had been captured in the fighting earlier were also permitted to enlist. This group was organized as the 40th Battalion. The 41st and 42nd Battalions were depot battalions stationed in Plymouth, England. In his memoirs about the Legion Jabotinsky described the composition of the 5000-member Legion as; "thirty-four per cent from the United States, thirty per cent from Palestine, twenty-eight per cent from England, six per cent from Canada, one per cent Ottoman war prisoners, one per cent from Argentina." The soldiers of the 38th, 39th and later the 40th Battalions of the Royal Fusiliers served in the Jordan Valley and fought the Ottomans north of Jerusalem.

In June 1918, the volunteers of the 38th Battalion began engaging the Ottomans some twenty miles north of Jerusalem. In the fighting in the Jordan Valley, more than twenty Legionnaires were killed, wounded, or captured, the rest came down with malaria, and thirty of this group later died. The Legion then came under the command of Major-GeneralEdward Chaytor,[9] who commanded the ANZAC Mounted Division.

Besides various skirmishes, the Legion also participated in the Battle of Megiddo in mid-September, 1918, widely considered to have been one of the final and decisive victories of the Ottoman front.

The Legion's mission was to cross the Jordan River. Jabotinsky led the effort. Later, he was decorated and Chaytor told the Jewish troops: "By forcing the Jordan fords, you helped in no small measure to win the great victory gained at Damascus."

The cap badge of the First Judaeans 1919-1921: menorah and word קדימה Kadima

Almost all the members of the Jewish regiments were discharged immediately after the end of World War I in November 1918. Some of them returned to their respective countries, others settled in Palestine to realize their Zionist aspirations. In late 1919, the Jewish Legion was reduced to one battalion titled First Judaeans, and awarded a distinctive cap badge, a menorah with the Hebrew word קדימה Kadima (forward) at the base.

Former members of the Legion took part in the defence of Jewish communities during the Riots in Palestine of 1920, which resulted in Jabotinsky's arrest. Two former members of the Legion were killed with Trumpeldor at Tel Hai. One former member of the Legion was killed in Tel Aviv-Jaffa during the Jaffa riots of 1921. Some members of the Jewish Legion settled in moshav Avihayil. Another former member died in service in World War II.[11]

Gideon Mer,[13] physician, veteran of Zion Mule Corps, Jewish Legion and British Army in World War II. Served as medic in Israeli War of Independence; later worked in the Israeli Ministry of Health. {Note: he is the unnamed Officer during World War II in charge of anti-Malaria program mentioned in Martin Sugarman's article on the Zion Mule Corps}.

Lammfromm, Arnon, Izhak Ben-Zvi and the Commemoration of Joseph Binyamini: A Failed Attempt to Create a Site of National Heritage", Archion, 17, Winter 2013, pages 48–55, 68 (Hebrew and English abstract)